The present invention relates to rotating rectifiers. A rotating rectifier assembly is an electronic device that converts alternating current produced by rotating elements of electrical machinery into direct current. A common application for the rotating rectifier assembly is within a brushless generator.
A typical brushless generator includes an exciter and a main generator for converting the rotational energy generated by a prime mover into multiphase alternating current (AC). The exciter may include stationary field windings which develop a magnetic field when electrically coupled to receive a direct current (DC) voltage from a DC voltage source, such as a voltage regulator, voltage control device, or battery. The exciter may also include windings mounted on the generator rotor, which rotate within this magnetic field. During rotation, alternating current is induced in the exciter rotor windings. Typically, the exciter rotor windings are wound such that the induced alternating current is a three-phase alternating current. Rectifier circuits then convert three-phase AC from the exciter rotor windings into a DC output to supply to the main generator.
These rectifier circuits are electrically coupled between two sets of windings, both mounted on the generator rotor, resulting in the rectifier also being mounted on the generator rotor. For this reason, this type of rectifier circuit is often referred to as a rotating rectifier.
The semiconductor devices used in rectifiers dissipate power in the form of heat during operation. Without proper attention to cooling, the semiconductor devices may fail. Many traditional rotating rectifiers lack adequate mounting surface and heat sink area to be utilized in high temperature applications. Additionally, conventional solder mount components experience higher failure rates due to the generated heat and the centrifugal forces encountered during operation.